Speed changing mechanism



May 26, 1970 .1. E. WHITFIELD SPEED CHANGING MECHANISM 14 Sheets-Sheet l Filed Nov. 2o, 19e? .MAK w14 k v l. 1 1 k W@ m om om luism |l \mn -A.\w l. 0 m N .w Q h -n Y 0 II WQ/Hw mw ,x 1/ XN 4 A vm W IN V EN TOR.

Jose/fw f. NH/ rnn o BY J. E. WHITFIELD SPEED CHANGING MECHANISM 14 Sheets-Sheet 2 INVENTOR.

Jose-PH E h/fn fur/n0 May 26, 1970 Filed Nov. 20, 1967 May 26, 1970 .1. E. WHITFIELD SPEED CHANGING MECHANISM 14 Sheets-Sheet 5 Filed Nov. 20. 1967 INVENTOR. Josep E Nairn/no A rmt/v5 Y May 26, 1970 mea Nov. 2o. 19s? J. E. WHITFIELD SPEED CHANGING MEcHANIsM 14 Sheets-Sheet 4 75g. 2O v INVENTOR. Jose/w WH/rnao fra/@YE y May 26, 1970 .1J-:WHITFIELD 3,513,715

SPEED CHANGING MECHANISM Filed Nov. 20. 1967 14 Sheets-Sheet 5 INVENTOR.

../osfpH f. h/HlrF/ELD /4 TTM/v6 y VMuy 26', 1970 J. E. WHITFIELD SPEED CHANGING MECHANISM 14 sheets-sheet s Filed Nov. 20, 1967 m .Mok

INVENTOR. Joseph' E. WH/ rnno May 26, 1970 J. E. WHITFIELD SPEED GHANGING MEcaAmsu Filed Nov. 20, 1967 14 Sheets-Sheet 'l Hg. 39A

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INVENTOR. .Jost/QH E. WH/rno May 26, 1970 J. E. WHITFIELD SPEED CHANGING MECHANISM 14 Sheets-Sheet 8 Filed Nov. 20, 196'? INVENTOR. Jose-PH WH, rtf/no W y E N 4 4 m.. F O 6 2 5 4 9 F J. E. WHITFIELD MECHANISM 14 Sheets-Sheet 9 Filed Nov. 20, 196'? INVENTOR.

Jon-PH E. Vn/inno May 26, 1970 J. E. WHITFIELD 3,513,715

SPEED CHANGING MECHANISM Filed Nov. 2o. 1967 14 sheets-sheet 1o May 26, 1970 J. E. WHITFIELD SPEED CHANGING MECHANISM 14 Sheets-Sheet 1l E Filed NOV. 20, 1967 INVENTOR. Joss/sw E. WH, rra-o May 26 1970 J. E. WHITFIELD 3,513,715

SPEED CHANGING MECHANISM Filed Nov. 2o, 19e? 14 sheets-sheet v1,2

i l l A 364 374 365 374 :gl-lg| 7 8 INVENTOR Jcsf'PH E k/Hl rnno ATTORNEY Ml? 26, 1970 J. E. WHITFIELD 3,513,715

SPEED CHANGING MEGHAN I SM Filed Nov. 20. 1967 14 Sheets-Sheet 15 398 -f/ 396 L ;l E Ti 392 400 V" as@ u M :fn-L

= E I E 403 INVENTOR.

.JosePH E. wmrnno Amm/5 Y May 26, 1970 J. E. WHITFIELD SPEED CHANGING MECHANISM 14 Sheets-Sheet 14 Filed Nov. 2o. 1967 INVENTOR. Jose-PH. E. Wulff/sco Z 't 2.5%?" M United Staffa Patent U.S. Cl. 74-410 24 Claims ABSTRACT OF THE DISCLOSURE` Epicyclic gearing having either a sun or spur gear and coaxial internal gear with a plurality of planetary gears therebetween or compound gearing having two coaxial Vspur gears and compound outer gearsv connecting4 therebetween, and means to equalize the load upon all of the planetary and outer gears of either type by the employment of positive, non-flexible and/or incompressible elements or means which are arranged toA equalize any positive or negative loads upon the various planetary and outer gears by positive shifting of the operative positions thereof automatically in directions to effect equalizing of the loads on all of said planetary or outer gears.

BACKGROUND OF THE INVENTION In most ofthe equalizing systems now in use, exible or compressible material is usedin one of several forms to provide equalization. This is generally in the nature of a material which functions similarly to rubber and compresses or -flows under load. Quite'often metallic members are employed which are formed. so they can bend or flexunder load. Sometimes the entire gear mountings are intended to be exible enough to provide equalization. Such designs can never truly equalize and they produce lost motion in fluctuating loads, and their exibility can Vnot be controlled or altered.

Various layouts of levers, bell cranksand slotted solid blocks or rigid annular rings areused. Theseusually require sliding motion with line or point contacts for bearing loads. Most of these devices will not equalize more than three' gears. They are non-adjustable for backlash or wear and unsuitable for fluctuating loads. The angularity and working length of these various levers change with gear movement and therefore some equalization is lost. d

Most of these systems develop considerable lost motion sate for this leakage. Since there areY relative moving parts in such asystem, they alsofaresubjectto friction .Y

and wear. l

Three planetary gears may .quite easily be 4balanced mechanically. For. example, a three-way balancing vseesaw type device eanbe used as in Pats. Nos. 3,3l5547,3,315,-

i546 and 3,080,775. However, whenit is attempted to balance four gears in the same manner, the problem-becomes more diicult and many of the proposed solutions do not satisfactorily solve the problem. For example, in Pat. No. 3,292,460, especially FIG. 3, it is obvioussuch an arrangement will not equally balance the four gears under,` 4

are in proper position to receive their share of the load, and the third gear is in position to receive more than its share of the load while the fourth gear is in a position to all conditions. Let it be -assumedthat two adjacent gears receive no load. To correct the situation the third gearv` 3,513,715 Patented May 2 6,

must move in a negative direction and the fourth gear in a positive direction to provide equalization. The device lshow n can not accomplish such a movement.

Also, in the above-described arrangement, itmust be assumed that one or more of the gears'may requirev more movement of their centers than the other gears of a `device to provide equal loading. This changes the angles and effective lengths of the various levers and links and thus the gear load is not truly balanced as in a hydraulic system. As another example, in the same patent, No. 3,292,460, in FIGS. 4 through 8, suppose one of the gear centers was not equally spaced by a relatively large amount. This would greatly change the working angle of the eccentric ylevers and the uneven angle of the eccentric levers would alter their effective working length andl produce-an yunequal loading on the gear teeth. lThis isthe equivalent of a balancing lever in which the central balancing point is not in the exact center of the lever.

Such an adverse condition cannot develop with ahydraulic balancing system or any mechanical system'that is exactly equivalent to a hydraulic system, as in the present disclosures. The tooth loads will Ibe equal even when the gear spacing is considerably unequal.

SUMMARY OF THE INVENTION This invention relates to improvements in speed changing devices having a predetermined speed ratio and embodying epicyclic gearing, as well as simple compound gearing that can be substituted for such epicyclic gearing, and balancing systems used in such mechanisms to insure even load distribution to all of the gears in the trains.

In epicyclic gearing having a single sun gear and a single internal gear, it is customary practice to use a multiplicity of planetary gears as driving means between the sun gear and internal gear. The input and output shafts are in axial alignment.

In the compound gearing used as a substitute for the epicyclic gearing the input and output shafts are also in axial alignment. Each of the two shafts have a gear of unequal size attached to their inner end. yThese gears will be termed spur gears. Multiple sets of gears, each set consisting of two gears of unequal size, are spaced around the central spur gears and these gears are termed outer gears. The drive between the unequal sized spur gears is through the mating complementary outer gears.

It should be apparent that although structural differences exist between the epicyclic planetary gear arrangement and the compound gear arrangement the results are similar. Several optional designs of substantially equivalent speed reducers are disclosed herein but they all have certain common features. A completely self-contained and sealed hydraulic system may be used with each of the various gear arrangements as the equalization means. ln addition, optional mechanical means are provided which may be substituted for such hydraulic systems to achieve the desired results.

In regard to the gearing, two general arrangements are shown. One design has one sun gear, multiple planetary gears and an internal gear. A second design producing the same results has two spur gears, multiple compound spur gears and no internal gear. One spur gear serves the same purpose as an internal gear in the epicyclic planetary gear arrangement. All of the 'various equalization systems shownhave certain common features. All are of rigid material or non-compressible substance, there being no dependence upon any kind of flexible or compressible material. All the systems have positive movement balanced against negative movement, `as explained hereinafter, involving the principle of shifting of rgidmechanisms or non-compressible substances fromv a negatively loaded position to positively loaded position, in an equal degree, to provide a desired fixed speed ratio having no fluctuations o'r`lost motion'.

In the mechanical type Ibalancing systems, the balancing forces are transferred equally, the same as in a hydraulic system, even when more than three planetary gears or outer gears are used. For example, in a centrally balanced seesaw, `when one end is forced down by an unequal load'the other end must go up an equal amount. The same is true of all these balancing devices except that three or more loads must be balanced and controlled equally.

When more thanone planetary or outer gear is used in a speed changing mechanism, there is always the problem of ldividing the load equally among them. There are many reasons for this problem. The various parts can be machined exactly correct. Material is'somewhat elastic when under load and does notdelect equally. Due to heating, loading and'aging, metal will gradually change dimensional slightly. Wear also occurs unequally.

The principal object of this invention is to provide a geared speed changing device employing planetary or outer gears having balanced tooth loading.

Another object is to provide various gear layouts with a sealed hydraulic balancing system.

Another object is to provide such a device with gears having self-adjustable centers, the centers moving partially in an orbital path around the sun gear.

Another object is to provide such a device with the planetary or outer gears mounted on eccentric shafts which are controlled by a sealed hydraulic system.

Another object is to provide such a device with cornpound gearing having no internal gear and controlled by sealed hydraulic means.

Another object is to utilize displaceable metal wedges in lieu of the displacement of liquid in the aforementioned hydraulic designs to effect the desired load equalization between the planetary or outer gears.

Another object is to utilize radially displaceable rigid metal links to effect the desired load equalization between the planetary or outer gears.

Another object is to utilize axially displaceable metal linkage to effect the desired load equalization between the planetary or outer gears.

Another object is to provide optional designs of equalization in which the equalizing effect is not diminished because of Wear.

Another object is to provide a device `with equalization means for planetary or outer gears that will compensate for inaccurately located gear centers.

Another object is to provide a device with equalization features that will compensate for undersize planetary or outer gears.

Another object is to provide such a device with equalization features for planetary or Outer gears in which the same move axially to compensate for uneven gear loads.

Another object is to provide such a device having multiple gear sets, each set consisting of two gears, one gear of each set being helical and the other gear having straight teeth to provide equalization of loads upon the same.

'Another object is to provide such a device having a plurality of sets of multiple gears, each set having two gears and both gears of each set being helical to provide equalization.

To simplify and clarify or define the language in the specification and claims, it is intended to term any movement or condition that tends to move a gear away from the load to reduce its load as being negative or a negative movement; likewise, any movement or condition that tends to move a gear into the load to increase its load as being positive or a positive movement. As an example, a gear set having four outer gears may have two of the gears located to carry exactly one-fourth of the load each while a third gear may be located to carry one-half of the total load and the .fourth gear may be located to carry no load. To even the gear load the first two gears need not be shifted, the third gear should be shifted negatively to reduce its load and the fourth gear would be shifted in a positive direction to increase its load. This same sequence is true for any number of planetary or outer gears. If the balancing mechanism is correct, then the gears will be equally loaded because any gear that is overloaded will simply transfer part of its load to the underloaded gear or gears.

This invention provides for equal loading of all the planetary or outer gears in a simple, practical and economical manner, such even loading being maintained at all times regardless o-f slight errors in manufacturing, distortion due to load and normal wear, and any condition that tends to produce vuneven loads.

There is no change in the gear ratio between the input and output shafts due tothe slight shift in gear centers. The rotation lost by the negative movement of one or more gears is compensated for by the positive movement of one or more of the other gears. This is not possible when using flexible members as in certain prior devices.

In all the embodiments of this invention, there is a balancing action in which one or more of the gears is shifted in a positive direction to increase the load between when one or more of the other gears is shifted in a negative direction to reduce their load.

The underlying theory of all the embodiments disclosed is substantially exactly the same. For example, if a gear reducer has four or more planetary gears and each gear center is located and controlled by a hydraulic cylinder, then it would only be necessary to connect all these cylinders together and they would automatically balance each other precisely. However, due to leakage, it is necessary to employ a pump which is exterior to the system to compensate for this leakage. Accordingly, other designs are disclosed herein that perform similarly to hydraulic cylinders but are less complicated and have no leakage for which compensation must be made. Further, it is not essential that hydraulic fluid be used as a balancing means; any material or substance that can be displaced from one position to another may be used if the design is suitable for such use. Semi-solid fluids or dry pulverized materials may be used. Also, certain metal. shapes can be displaced to transfer movement from one or more overloaded gears to one or more underloaded gears. In the following specification, hydraulic balancing systems are described for a plurality of different gear arrangements to illustrate the range of application of the invention. The systems which require hydraulic fluid may be lled at assembly and permanently sealed against leakage so as to constitute a self-contained unit or system not dependent upon exterior sources of supply or power means.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view taken on line 1-1 of FIG. 2 and showing an internal gear that revolves.

FIG. 2 is a cross-section taken through FIG. 1 on line 2 2.

FIG. 3 is a diagrammatic view of the hydraulic bellows and connections as used in FIGS. 1 and 2.

FIG. 4 is a longitudinal sectional view taken through the axis of a unit similar to FIG. 1 except herein the internal gear is stationary and the planetary gears are carried around the sun gear.

FIG. 5 is a cross-section through the planetary gear carrier taken on line 5 5 of FIG. 6.

FIG. 6 is a face view of the carrier.

FIG. 7 is another cross-section thro-ugh the carrier shown in FIG. 6, on line 7-7 thereof.

FIG. 8 is a side view of the bellows support of the unit shown in FIGS. l and 2.

FIG. 9 is an end View of the support shown in FIG. 8.

FIG. l0 is an edge view of the bellows support as used in FIG. 4.

FIG. ll is an outside end view of the support shown in FIG. l0.

FIG. 12 is a side view of the same support showing oil rts. pFIG. 13 is a cross-section taken on line 13-13 of FIG. 12 of the support and showing said oil ports herein.

FIG. 14 is a longitudinal sectional view taken through the axis of another embodiment of gear unit as seen on line 14-14 of FIG. 15.

FIG. 14A shows the centers of the end portions of the eccentric shafts being inside the circle formed by the centers of the planetary gears.

FIG. 14B shows the centers of the end portions of the eccentric shafts being outside the circle formed by the centers of the planetary gears. Both FIGS. 14A and 14B are shown out of regular scale for clarity.

FIG. 15 is a cross-sectional view taken on line 15-15 of FIG. 14.

FIG. 16 is a partial cross-sectional view taken on line 16-16 of FIG. 14 and showing the bellows for two-way operation.

FIG. 17 is an end view of the outer gear eccentric shafts for the unit of FIGS. 14 and 15 and showing a control arm thereon.

FIG. 18 is a side view of the eccentric shaft shown in FIG. 17.'

FIG. 19 is a diagrammatic view of the bellows and connections as used in the unit shown in FIGS. 14 and 15.

FIG. 20 is a longitudinal sectional view of another embodiment of gear unit taken through the axis thereof and showing compound gearing having no internal gear.

FIG. 21 is an optional design of the gear assembly of the unit shown in FIG. 20.

FIG. 22 is an optional design for the bellows layout of the unit shown in FIG. 20.

FIG. 23 is an end view of the thrust cage per se shown in FIG. 22.

FIG. 24 is a longitudinal sectional View of unit similar to that shown in FIG. 20 except that it illustrates a different balancing arrangement from that shown in FIG. 20.

FIG. 25 is a fragmentary sectional view of the bellows arrangement as taken on line 25-25 of FIG. 24.

FIG. 26 is a side view of the eccentric shaft of FIG. 24 showing a control arm thereon.

FIG. 27 is another side view of the eccentric shaft of FIG. 24 showing an edge view of the control arm.

FIG. 28 is a sectional view of one-half of a gear coupling used in the embodiment of gear unit shown in FIG. 3l and having a drive pin indicated thereon in phantom.

FIG. 29 is a side view of the drive pin shown in FIGS.

Y 31 and 32.

FIG. 30 is an edge view of the drive pin shown in FIGS. 31 and 32.

FIG. 31 is a longitudinal sectional view of still another embodiment of gear unit as seen on line 31-31 of FIG. 32, said embodiment being similar to FIG. 1 except the balancing mechanism is mechanical instead of hydraulic.

FIG. 32 is a cross-sectional view of the unit shown in FIG. 31 taken on line 32-32 of FIG. 31.

FIG. 33 is a longitudinal sectional view of still another embodiment of gear unit and is similar to that shown in FIG. 14 except that a mechanical means of equalization is shown instead of a hydraulic bellows system.

FIG. 34 is a side view of the assembled balancing Wedges per se as seen on line 34-34 of FIG. 33, but only one eccentric shaft with its two control arms being shown in position with said assembly.

FIG. 35 is a view similar to FIG. 34 except that the wedges are shown in an uneven position, as is possible during operation and showing two control shafts with control arms partly broken away for clarity.

FIG. 36 is a plan view of a plurality of the control arms on the eccentric shafts in association wedges illustrated fragmentarily.

FIG. 37 is a side view of a wedge per se of the type shown in FIGS. 33 to 36.

FIG. 38 is an end View of such wedge.

FIG. 39 is an end view of an eccentric shaft per se and its two control arms for the unit of FIGS. 33 to 36.

FIG. 39A shows a control arm similar to those in FIG. 39 but provided with wear adjustment means.

FIG. 40 is a longitudinal sectional view of still another embodiment of gear unit which is somewhat similar to that shown in FIG. 20 except that mechanical means is substituted for the hydraulic bellows shown in FIG. 20.

FIG. 41 is a fragmentary cross-sectional view taken on line 41-41 of FIG. 40.

FIG. 42 is an optional design of the double acting bell crank for the unit shown in FIG. 40.

FIG. 43 is a plan view showing the optional concave seats for the spherical self adjusting shoes.

FIG. 44 is a fragmentary sectional view of an optional embodiment of means to connect the linkage equalization system to the planetary gear shafts of the ernbodiment of gear unit shown in FIG. 52.

FIG. 45 is a fragmentary end view of the mechanism shown in FIG. 44.

FIG. 46 is a longitudinal sectional View of a still further embodiment of gear unit somewhat similar to that shown in FIG. 14 except that a linkage mechanism is used for equalization instead of the hydraulic bellows shown in FIG. 14.

FIG. 47 is a side view of the linkage seen on line 47-47 of FIG. 46.

FIG. 48 is a plan view of the linkage of FIG. 47 opened out flat and connected to one eccentric shaft.

FIG. 49 is a fragmentary side view of an eccentric shaft with an adjustable control arm.

FIG. 5() is an end view of the adjustable control arm shown in FIG. 49.

with a pair of FIG. 51 is a plan view of a half link that is necesv sary when an odd number of planetary gears are used.

FIG. 52 is a longitudinal sectional View through a still further embodiment of gear unit somewhat similar to that shown in FIG. 40 except an internal gear system is used and links are employed for load equalization control.

FIG. 53 is a side View of the assembly of links only of the unit shown in FIG. 52.

FIG. 54 is a sectional view of the links as seen on lines 54-54.

FIG. 55 is a side View of the equalization bell crank of the unit shown in FIG. 52.

FIG. 56 is an end view of the bell crank shown in FIG. 55.

FIG. 57 is a side view of the self-aligning joint for the bell crank as shown in FIG. 52.

FIG. 58 is a longitudinal sectional view through a further embodiment of gear unit which is somewhat similar to that shown in FIG. 52 except that a double set of one-Way linkages is used to control load equallzation.

FIG. 59 is a side view of one of the sets of links shown in FIG. 58.

FIG. 60 is an edge view of a set of the links shown in FIG. 59'.

FIG. 61 is an optional design of the linkage and linkage control means for the unit shown in FIG. 58.

FIG. 62 is a longitudinal sectional view through another embodiment of gear unit somewhat similar to that shown in FIG. 40 except that a wobble plate is used to provide load equalization when three outer gears are used.

FIG. 63 is an optional design of an outer gear shaft which may be used with the structures illustrated in FIGS. 64-66.

FIG. 64 is an optional design of an outer gear actuating member which may be substituted for the wobble plate shown in FIG. 62.

FIG. 65 is a section through the member shown in FIG. 64 taken on the line 65-65 thereof.

FIG. 66 is a side view of still another structure which may be used instead of the wobble plate shown in FIG. 62 when four gears are used.

FIG. 67 is an edge view of one of the balancing levers included in the structure shown in FIG. 66.

FIG. 68 is an edge view of the center balancing member of FIG. 66.

FIG. 69 is a longitudinal sectional view through 'a still further embodiment of gear unit somewhat similar to that shown in FIG. 40. y

FIG. 69A is an enlarged elevation of one end of an outer gear shaft provided with hydraulic bellows means to achieve equalization when the outer gears themselves are slightly unequal. v

FIG. 70 is a longitudinal sectional View through a device similar to that of FIG. 69 except that'one spur gear and one internal gear are used instead of two spur gears as in the unit of FIG. 69.

FIG. 70A shows the wobble plate of FIG. 62 used in connection with the gears of FIGS. 69 and 70.

FIG. 71 is a diagrammatic sectional view of a hydraulic balancing means -Which may be substituted `for the mechanical links shown in FIGS. 47-48 for the unit illustrated in FIG. 46.

FIG. 72 is a side view of a hydraulic balancing device which may be substituted for the mechanical balancing devices shown in FIGS. 62, 64 and 66.

FIG. 73 is a fragmentary sectional view of the hydraulic device shown in FIG. 72.

FIG. 74 is a hydraulic balancing device which may be substituted for the balancing wedges shown in FIGS. 33 and 40.

FIG. 75 is a cross-sectional view of the device shown in FIG. 74.

FIG. 76 is a fragmentary exterior view of the hy draulic device shown in FIG. 74 and illustrates one eccentric shaft and the two control arms thereon.

FIG. 77 shows the manner of operation of an undersize gear in a planetary gear train.

It is to be observed from the following description of the various embodiments of the invention that they have in common the following beneficial attributes and characteristics which distinguish them over the known prior art: n

(1) All load-carrying engagements in the balancing systems provide for relatively large two-dimensional surface area wearing surfaces which makes them superior to known, less desirable, but operable designs.

(2) All the balancing systems are manually and/or self-adjustable for zero clearance at assembly and are manually or self-adjustable to compensate for Wear.

(3) All the optional gear design layouts are illustrated and described as having a sealed hydraulic balancing system; and for each of these hydraulic balancing systems there is provided a mechanical balancing system to produce substantially the same results in the same space and in substantially the same manner.

(4) In all the balancing arrangements disclosed, the balancing pressure remains constantially equal even when a relatively large movement of one or more gears is required to effect balance of the gears.

(5) In all the designs disclosed, none of the planetary or outer gears can carry any load until all the gears are equally loaded.

(6) In all the designs disclosed, all lost motion can be eliminated from the valancing system and there will be no Abacklash when driving a fluctuating load.

(7) No lost motion occurs when the unit is reversed.

(8) All the embodiments and designs, except a simplified version of one of the major designs, can be -used with more than three planetary or outer gears and maintain theoretically perfect equalization.

In all these disclosures veither a double acting single system or single acting double system of equalization is used and this provides for the pre-loading of the systern for forward rotation against reverse rotation to eliminate all backlash.

DESCRIPTION OF THE PREFERRED EMBODIMENTS To simplify the descriptions, longitudinal sectional views of a limited number of optional designs having hydraulic balancing systems are shown first in the drawings and described first in the specification. These are FIGS. 1, 4, 14, 20 and 24. The remainder of the designs shown all have mechanical equalization means as optional designs for the hydraulic systems.

The speed changing devices described herein have been termed speed reducers throughout the specification and claims for purposes of simplicity. However, it is to be understood that all of these designs may be used as yspeed increasers. When used as speed increasers the shafts designated as input shafts become the output shafts and the designated output shafts become the input shafts. In a few other instances, other slight changes may be necessary in the description but this will be understood by those skilled in the art.

Referring to FIG. 1, the sun gear 2 is fixed to the input shaft 4, one end of shaft 4 being journaled in the housing end wall -6 while the other end of the shaft is journaled in the hollow output shaft 8. The sun gear 2 meshes with the outer gears 10 and these mesh with the internal gear 12. The internal gear 12 is fixed to and concentric with the output shaft `8. The gears 10 are rotatable on the shafts 14 and the shafts 14 are journaled in the carriers 16. The carriers 16 are arcuate on their outside and inside surfaces and are free to slide in the circular guideways 18-20, the guideway 18 being in the end wall 6 and the guideway 20 being in the circular support 22. The housing 24 and the end wall 6 complete the outside structure and carry the bearings for the shafts 4 and 8.

It will be obvious from the foregoing that if the sun gear is the input or driving gear, the internal gear 12 will be the driven gear, and vice versa. Therefore, for convenience, in the following description relative to FIGS. 1 and 2, as well as in the descriptions hereinafter concerning the other succeeding figures, and also in the appended claims, the driving and driven gears shall be referred to commonly as drive gears.

In FIG. 2, the carriers 16 are shown as being located in the circular guideway 18. A bellows support 26 is rigidly fixed in the guideways between the ends of the carriers 16. A bellows 28 is placed between each end of the carriers 16 and the bellows support 26 to control the movement of the carriers 16 and their gears 10. The bellows 28 are connected as shown in FIG. 3 by the tubing 30. One set of bellows is required for each direction of rotation. The bellows 28 are filled and sealed after assembly, and the planetary gears 10 are properly located thereby.

In operation, the input shaft 4 turns the sun gear 2 and the sun gear rotates the gears 10 about their slightly shiftable axis. Thev gears 10 rotate the internal gear 12 at a reduced speed'and in the opposite direction of the input shaft. The internal gear 12 is fixed to and rotates the output shaft 8.

The input load and the output load places a load on the gears 10 and these gears create a force against the ends of the carriers 16. If there were no bellows 28 and support 26, the gear carriers 16 could simply slide in the guideways 18 and 20 and the internal gear would remain stationary. However, the gear carriers 16 are restrained from sliding in the guideways by the bellows 28 and bellows support 426. To-evenly load the gears 10, oil may 9 ow from one of the bellows' to anotherA to equalize the load as shown in FIG. v3. The bellows are-filled through connections 32-32 and such Vconnections then are closed tightly to form a closed, leak-proof system.

FIG. 4 shows a design similar to FIGS. 1 and 2 except in this instance, the internal gear is stationary and the planetary gear assembly is fixed to and turns with the output shaft 46. The sun gear 34 is fixed to the input shaft 36 and the sun gear operates withthe planetary gears 38 and the planetary gears 38 operate with the internal gear 40. Since the internal gear 40 is stationary in this design, when in operation, the planetary gears revolve on their own shafts 42 and are also carried around the sun gear 34. A circular guideway is cut into the face of the ange 44, the flange being xed to the output shaft 46. Likewise a circular guideway is cut into the circular mating flange 48. A bellows support 50 is fixed between the flanges 44 and 48 in the circular guideway and the bellows 52 are attached to the supports S0.

rIhese are two concentric, annular oil grooves 54in the flange 48-and one of these oil grooves is connected to the forward set of bellows 52 while the other groove 54 is connected to the rear set of bellows through the holes 56. The oil grooves 54 are iilled through the fittings 58 at assembly, which are then closed tightly to form a closed, leak-proof system.

In operation, the internal gear 40 is iixed and when the input shaft 36 is rotated, the planetary gears 38 rotate on their shafts 42 and also are carried around the sun gear 34. Similar to FIG. 2, the planetary gear carrier 60 bears against the bellows 52 and the bellows are fastened to the support 50. Since the support 50 is fixed to the anges 44 and 48, these anges and output shaft must turn when the input shaft rotates. The output shaft turns in the same direction as the input shaft but at a lower speed.'

Thus, FIGS. 1 and 4 are similar except that, in FIG. 1, the internal gear 12 revolves to drive the output shaft, while in FIG. 4 the planetary gears are carried around the sun gear to drive the output shaft while internal gear 40 remains stationary. The housing 62 and cover 64 complete the structure.

FIG. 14 is a longitudinal sectional view through a device that is optional for use with the structures of FIGS. 1 and 4. The gearing and the input and output shafts of FIGS. 14-15 are similar to those in FIGS. l and 2. However, in this instance the gears 70 are mounted on eccentric shafts 72, the eccentric shafts being mounted in a stationary member and the eccentric shafts are controlled by hydraulic bellows to provide a small amount of rotation and thus change the gear centers slightly to provide even gear tooth loading. The operation is as follows:

The input shaft '66 carries the sun gear 68 and rotates therewith. The sun gear meshes with the gears 70 which,

' in turn, mesh with the internal gear 84. The gears 70 are mounted on the veccentric shafts 72 and the eccentric shafts are mounted in the stationary end wall 74. The eccentric shafts 72 have a control arm 76 which controls ythe rotation of the shafts. The control varm '76 is mounted between two bellows 78 and the bellowsare mounted between two fixed supports 80. The bellows 78 :are connected in positive and negative directional sets,'as

shown in FIG. 19, through the tubing 82. The internal gear 84 is attached to and concentric with the output shaft 186. f v

When in operation under load, should one or more gears receive more than their share of the load, then Vthe load on the eccentric shafts 72 will also be unequal. This excess load on one gear will be reflected in an excess load on the control arm 76 land on one of the bellows 78. This excess pressure in one of the bellows will flow to the other bellows and increase their pressure to the average pressure in the system. Thus when one gear moves in a negative directionto release part of its load, one or more of the other gears are moved ina: positive direction to increase their load andthusreach anequalization among the gears. f

The eccentric shafts 72 have an olset central portion 92 which carries the gears 70 and this central portion is eccentric to the two end bearing portions 94 and 96, .the two end portions being in axial alignmentwith each other. The amount of eccentricity, or offset, of the central portion 92 of the shafts in relation to the end portion is usually relatively small, or about one eighth inch, depending upon the size of the speed reducer. It is assumed `such a unit can be made with reasonably accuracy and that it is not necessary to compensate for more than a few thousandths of an inch. With modern gear cutting equipment, the gears themselves should require very little movement for equalization.

Assuming the gears to be accurate and all the inaccuracies are in the associated parts, then there will be no continuous movement of the eccentric shafts after the gears become equally loaded. The gears themselves are relatively rigid and will deform very little underv load. However, the shafting, housing andend wall will deflect under load due to stress, heat and vibration, and -the eccentric shafts will compensate for this condition by a very slight rotation. As a further correction for uneven loading, self-aligning bearings should be used in all the planetary or outer gears. They are not shown however, to simplify the drawings. Also, antifriction bearings should preferably be used throughout the devices instead of the journal bearings or bushings, as shown. However, these details need not be shown to properly disclose the invention.

It will be noticed in FIGS. 14 and 15 that a full complement of outer gears may be used. Five are shown and the gear reduction is about 1 to 3.00. Should the reduction ratio be, for example, about 1 to 1.25, then eight or ten outer gears could be used as they would be much smaller. The greater the number of outer gears that are used, the greater the amount of power that can be transmitted. Also, the greater the number of outer ygears being used, the greater the necessity for a simple and accurate equalization mechanism. The proposed devices are suitable for any number of gears that can be installed in the units.

In the foregoing embodiment, when one or more gears move in a negative manner to reduce their load, one or more yof the other gears must move forward in a positive direction to increase their load. This situation would be easy to visualize if only two outer gears were used and they were mounted on opposite ends of a cross-arm similar to a walking beam. The center of the cross-arm would be attached to a oating member, such as 182 in FIG. 31. Such a mechanism would provide for improperly spaced outer gear shaft centers and also compensate forvinaccurately cut gears. When more than two outer gears are used, the mechanism for equalization is not-assimple as for two gears but the total results must be exactly the same; that is, as one or more gears move negatively out of overload, others must move forward in a positive direction into the load.

The bellows shown in FIGS. 14,116 and,19' as stated before, are connected in positive and negative directional sets through the two sets of tubing 8 2. This provides for eqaulization under load in both directions. Only one set of bellows is necessary for one-way operation."

In actual practice either the driver or driven machine may have an uneven torque. condition and the load may be of a pulsating nature. Thus the load on the gear teeth may shift from positive to negative quite often and sequenially when in operation. To function successfully, all equalization devices mustbe without undesired backlash under such conditions. All the devices in in this application provide for the removal of all backlash during reversal of tooth loading due to lost motion in the equalization mechanism. Also, this lost motion can be reduced to zero with the adjustments provided therein. All, point and-line contacts have been eleminated and replaced by area con- 11 tacts throughout all the optional designs. These area contacts provide good bearing surfaces for long life without adjustment of any kind.

In the event some resilience is desired in the gearing, such resilience can be obtained by adding an expansion chamber 97 to the system, as shown in FIG. 3. The piston in the expansion chamber operates against a spring and compressed air. Also, two expansion chambers may be used to provide resilience in opposite directions. Since liquid is considered non-compressible, it is not necessary to use pressure in filling the bellows. Also, since the hydraulic systems are sealed, it is not necessary to re-fill them when in use and no oil pump, external or otherwise, is required as part of the gear devices.

FIG. 20 is a longitudinal Asectional view through an optional design of a compound gear speed reducer in which no internal gear is used but instead, compound gearing with two spur gears is used, the extra spur gear serving as the internal gear. In this design the outer gear centers do not shift or change centers to affect equalization. The operation is as follows: Power is applied at the input shaft 98 to which the small spur gear 100 is attached. The spur gear meshes with and operates the large gears 102 and the large gears are attached to and in axial alignment with the small gears 104. The small gears 104 mesh with and drive the large spur gear 106 and the large spur gear is attached to the output shaft 108. Thus, when the input shaft 98 is rotated, the output shaft 108 is rotated with increased torque in the same direction but a lower speed. It will be noticed that the teeth on gears 104 and 106 are straight or spur. The teeth on gears 100 and 102 are helical. When the input shaft 98 is operated under load in the direction of the arrow A, there will be axial thrust to the right as indicated yby arrow B. This thrust is opposed by the thrust bearing 110.

The aforementioned thrust on the spur gear 100 is produced by the thrust of the gears 102, this thrust being in the opposite direction as shown by the arrows C. Thus, when in operation, under load, all the gears 102 will try to move axially as shown by arrow C. This axial load is carried by the thrust bearings -112 into the thrust cage 114 and the axial movement of the thrust cage 114 is controlled by the bellows 116. The bellows are connected in positive and negative direction, as shown in FIG. 3 and described relative to FIG. 19. Naturally, if the gears 102 and 104 were both straight tooth gears, or certain combinations of complementary helical gears, no change in tooth loading or timing will occur with axial movement. With the disclosed design, for example, if the gear 100 is held against rotation and the gear set 102 and 104 is moved axially, then the large gear 106 will rotate slightly.

As another example, assume the gears 100 and 106 are held stationary and also one set of the outer gears are held axially and against rotation; the spur gears are both locked. If a second set of gears 102 and 104 are rolled, in mesh, and in a planetary manner, partially around the two spur gears then this set of gears will move axially as they are being rolled. This axial movement is caused by the relical gears 100402. In FIG. 20, again assuming the four lower gears all to be stationary, if the upper set of gears is rolled forward (toward the viewer) in mesh, then this set of gears 102 and 104 will move axially to the right as shown by arrow D. Also, if the same set of gears is rolled backward (away from the viewer) in mesh, then this set of gears will move axially to the left as arrow E.

The gears 102 and 104 must be of different diameter to produce the desired results. All the gears in both gear trains may be helical but the helix angle of the two gear trains must be different so that an unbalanced axial thrust is produced in one certain direction for one direction of rotation and this axial thrust direction must be reversed when the direction of rotation is reversed. For example, the low speed gears 104 and 106 could have a very gentle helix angle and the high speed gears 100 and 102 could have a steep helix angle. IIf all the gears were spur gears, then they could not be rolled in a planetary manner with both sun gears stationary and would mesh only at certain specific locations. For an equivalent design with all spur gears, the gears and spacing would have to be extremely accurate for equal gear loading. Such accuracy is considered impractical to produce and maintain. When in operation under load, this type of compound gear sets produce an axial thrust because of the helical gears and by balancing this thrust the gear loading is also balanced without shifting the gear centers. An optional method of connecting the bellows 116 is shown in FIG. 22. The bellows and thrust cage 114 may be assembled as a unit.

FIG. 2l shows another optional method of connecting the bellows in which a non-rotating shaft is used. This design eliminates the thrust cage 114 and is a generally simplified design. For reasons of simplicity the gears 102 and 104 are reversed from that shown in FIG. 20 but this is of no consequence to the invention. The bollows again are connected in positive and negative directional sets as shown in FIG. 3. A key is shown to prevent the planetary gear shaft 124 from rotating. In this FIG. 20, a thrust bearing is shown on one end of the drive shaft 98 While the other end of the drive shaft is carried in the hollow output shaft 10S. Naturally, the faces of the gears will not necessarily be even, as shown, when loaded equally. The axial thrust of the outer gears is carried into the thrust cage 114 and by the bellows 116 into the support 118 and the stationary housing. This support is drilled to deliver oil to the negative and positive bellows as shown. See FIG. 19 for the bellows connections.

The bellows 116 may be fixedly attached to the support 118 to prevent leakage and this assembly may be inserted into the thrust cage 114 after the remainder of the unit is assembled. The thrust cages 114 are round and free to slide, but not rotate in the bores of the housing 120. Because a double system of bellows is shown, this unit will operate in either direction. The radial bearings 126 are free to slide sideways in the housing end wall 122. The housing end wall is centered in the housing by the joint 128 which provides for precise alignment of the internal parts. The housing and end wall 122 completes the enclosure of the operating parts. The gear centers do not shift in this design. Axial movement of the outer gears provide for perfect equalization.

With reference to helical gears, to render the specification and claims clear and simplify the description of operation thereof, reference to the hand of a helical gear means it may be right hand or left hand; that is, the helix may twist to the right or to the left. The amount of rate of twist is measured in degrees. A gear with 15 twist would be considered a gentle twist and a gear with 45 would be considered a steep twist. In FIG. 20, the large helical gear is right hand with a gentle helix of 15. The gear 100 must be opposite and is left hand with a 15 helix angle. This explanation is intended to simplify some of the later description herein.

FIG. 24 is a longitudinal sectional view and shows another optional design somewhat similar to FIG. 20 in that it has compound gearing and is without an internal gear. However, the action of the equalization mechanism is different. In this design all gears must be helical. The operation is as follows:

The small inner spur gear 130 is attached to the input shaft 132. and meshes with the large outer gear 134, the large outer gear is fixed axially to the small outer gear 136, and this gear 136 meshes with the large spur gear 138 which is fixed to the output shaft 140, thus completing the gear train system.

The helix angle of the two gears 130 and 138 must be the same hand (left is shown) but not necessarily the same degree of twist or helix angle. Likewise, the helix angle of the two gears 1.34 and 136 must be the same hand (right is shown) but `with the degree of twist complementary to the spur gear with which they mesh. When 

